--- /dev/null
+// Copyright (C) 2021 Harry Godden (hgn) - All Rights Reserved
+
+SHADER_DEFINE( shader_ui,
+
+ // VERTEX
+ "layout (location=0) in vec2 a_co;" // i16, i16, .. ?
+ "layout (location=1) in vec2 a_uv;" // i16, i16
+ "layout (location=2) in vec4 a_colour;" // u32
+ "layout (location=3) in vec4 a_clip;" // i16, i16, i16, i16
+ "uniform mat3 uPv;"
+ ""
+ "out vec2 aTexCoords;"
+ "out vec4 aColour;"
+ "out vec2 aWsp;"
+ "out vec4 aClip;"
+ ""
+ "void main()"
+ "{"
+ "gl_Position = vec4( uPv * vec3( a_co, 1.0 ), 1.0 );"
+ "aTexCoords = a_uv * 0.0078125;"
+ "aColour = a_colour;"
+
+ "aWsp = a_co;"
+ "aClip = a_clip;"
+ "}",
+
+ // FRAGMENT
+ "uniform sampler2D uTexGlyphs;"
+ "out vec4 FragColor;"
+ ""
+ "in vec2 aTexCoords;"
+ "in vec4 aColour;"
+ ""
+ "in vec2 aWsp;"
+ "in vec4 aClip;"
+ ""
+ "void main()"
+ "{"
+ "float clip_blend = step( aWsp.x, aClip.z ) * step( aWsp.y, aClip.w ) * step( aClip.x, aWsp.x ) * step( aClip.y, aWsp.y );"
+ "vec4 glyph = vec4(1.0,1.0,1.0,1.0);"
+
+ "if( aColour.a == 0.0 )"
+ "{"
+ "glyph = texture( uTexGlyphs, aTexCoords );"
+ "glyph.a = smoothstep( 0.47, 0.53, glyph.r );"
+ "}"
+ "else"
+ "{"
+ "glyph.a = aColour.a;"
+ "}"
+
+ "FragColor = vec4( aColour.rgb, glyph.a*clip_blend );"
+ "}"
+ ,
+ UNIFORMS({ "uPv", "uTexGlyphs" })
+)
+
+// Types
+// ===========================================================================================================
+
+typedef i16 ui_px;
+typedef u32 ui_colour;
+typedef ui_px ui_rect[4];
+typedef struct ui_ctx ui_ctx;
+typedef struct ui_colourset ui_colourset;
+
+// Relative to cursor p0
+enum ui_text_align
+{
+ k_text_align_left = 0,
+ k_text_align_right = 1,
+ k_text_align_center = 2
+};
+
+struct ui_colourset
+{
+ union
+ {
+ struct
+ {
+ ui_colour main;
+ ui_colour hover;
+ ui_colour active;
+ };
+ struct
+ {
+ ui_colour background;
+ ui_colour bar;
+ ui_colour bar_hover;
+ };
+ };
+};
+
+struct ui_ctx
+{
+ struct ui_qnode
+ {
+ ui_rect rect;
+ ui_colour colour;
+ int mouse_over;
+ int capture_id;
+ }
+ stack[ 32 ];
+
+ #pragma pack(push,1)
+ struct ui_vert
+ {
+ ui_px co[2]; //32 4
+ u8 uv[2]; //16 2
+ u32 colour; //32 4
+ ui_rect clip; //64 8
+ }
+ *verts;
+ #pragma pack(pop)
+
+ u32 num_verts;
+ u16 *indices;
+ u32 num_indices;
+
+ ui_rect clipping;
+ ui_rect cursor;
+ u32 stack_count;
+ u32 capture_mouse_id;
+ int capture_lock;
+ u32 id_base;
+ int glyph_base;
+
+ // User input
+ ui_px mouse[2];
+ int click_state; // 0: released, 1: on down, 2: pressed, 3: on release
+
+ ui_colourset *colours;
+
+ GLuint vao;
+ GLuint vbo;
+ GLuint ebo;
+
+ struct ui_image
+ {
+ ui_rect rc;
+ GLuint image;
+ }
+ images[16];
+ int image_count;
+};
+
+// Globals
+// ===========================================================================================================
+
+#define UI_GLYPH_SPACING_X 9
+
+static GLuint ui_glyph_texture = 0;
+static ui_colourset ui_default_colours = {
+ .main = 0xff807373,
+ .hover = 0xff918484,
+ .active = 0xffad9f9e
+};
+
+static ui_ctx ui_global_ctx;
+
+// Initialization
+// ===========================================================================================================
+
+static void ui_init_context( ui_ctx *ctx, int index_buffer_size )
+{
+ u32 vertex_buffer_size = (index_buffer_size+(index_buffer_size/2));
+
+ // Generate the buffer we are gonna be drawing to
+ {
+ glGenVertexArrays(1, &ctx->vao);
+ glGenBuffers( 1, &ctx->vbo );
+ glGenBuffers( 1, &ctx->ebo );
+ glBindVertexArray( ctx->vao );
+
+ glBindBuffer( GL_ARRAY_BUFFER, ctx->vbo );
+
+ glBufferData( GL_ARRAY_BUFFER, vertex_buffer_size * sizeof( struct ui_vert ), NULL, GL_DYNAMIC_DRAW );
+ glBindVertexArray( ctx->vao );
+
+ glBindBuffer( GL_ELEMENT_ARRAY_BUFFER, ctx->ebo );
+ glBufferData( GL_ELEMENT_ARRAY_BUFFER, index_buffer_size * sizeof( u16 ), NULL, GL_DYNAMIC_DRAW );
+
+ u32 const stride = sizeof( struct ui_vert );
+
+ // XY
+ glVertexAttribPointer( 0, 2, GL_SHORT, GL_FALSE, stride, (void *)offsetof( struct ui_vert, co ) );
+ glEnableVertexAttribArray( 0 );
+
+ // UV
+ glVertexAttribPointer( 1, 2, GL_UNSIGNED_BYTE, GL_FALSE, stride, (void *)offsetof( struct ui_vert, uv ) );
+ glEnableVertexAttribArray( 1 );
+
+ // COLOUR
+ glVertexAttribPointer( 2, 4, GL_UNSIGNED_BYTE, GL_TRUE, stride, (void *)offsetof( struct ui_vert, colour ) );
+ glEnableVertexAttribArray( 2 );
+
+ // CLIPPING
+ glVertexAttribPointer( 3, 4, GL_SHORT, GL_FALSE, stride, (void *)offsetof( struct ui_vert, clip ) );
+ glEnableVertexAttribArray( 3 );
+ }
+
+ // Initialize default context
+ {
+ ctx->verts = (struct ui_vert *)malloc( vertex_buffer_size * sizeof(struct ui_vert) );
+ ctx->indices = (u16*)malloc( index_buffer_size * sizeof(u16) );
+
+ if( !ctx->colours )
+ ctx->colours = &ui_default_colours;
+ }
+}
+
+static void ui_context_free( ui_ctx *ctx )
+{
+ glDeleteVertexArrays( 1, &ctx->vao );
+ glDeleteBuffers( 1, &ctx->vbo );
+ glDeleteBuffers( 1, &ctx->ebo );
+
+ free( ctx->verts );
+ free( ctx->indices );
+}
+
+static void ui_default_init(void)
+{
+ // Load default font
+ u32 compressed[] = {
+ #include "vg/vg_pxfont.h"
+ };
+
+ u32 pixels = 0, total = 256*256, data = 0;
+ u8 *image = malloc( total );
+
+ while( pixels < total )
+ {
+ for( int b = 31; b >= 0; b-- )
+ {
+ image[ pixels ++ ] = (compressed[data] & (0x1 << b))? 0xff: 0x00;
+
+ if( pixels >= total )
+ {
+ total = 0;
+ break;
+ }
+ }
+ data++;
+ }
+
+ glGenTextures( 1, &ui_glyph_texture );
+ glBindTexture( GL_TEXTURE_2D, ui_glyph_texture );
+
+ glTexImage2D( GL_TEXTURE_2D, 0, GL_R8, 256, 256, 0, GL_RED, GL_UNSIGNED_BYTE, image );
+
+ vg_tex2d_clamp();
+ vg_tex2d_nearest();
+
+ free( image );
+
+ // Setup OpenGL memory
+ SHADER_INIT( shader_ui );
+ ui_init_context( &ui_global_ctx, 20000 );
+}
+
+static void ui_default_free(void)
+{
+ glDeleteTextures( 1, &ui_glyph_texture );
+ ui_context_free( &ui_global_ctx );
+}
+
+static struct ui_vert *ui_fill_rect_uv( ui_ctx *ctx, ui_rect rect, u32 colour, ui_px uv[4] );
+static void ui_draw( ui_ctx *ctx, m3x3f view_override )
+{
+ u32 num_indices_normal = ctx->num_indices;
+
+ // Append images to back of buffer
+ for( int i = 0; i < ctx->image_count; i ++ )
+ ui_fill_rect_uv( ctx, ctx->images[i].rc, 0xffffffff, (ui_px[4]){0,0,128,128} );
+
+ glBindVertexArray( ctx->vao );
+
+ glBindBuffer( GL_ARRAY_BUFFER, ctx->vbo );
+ glBufferSubData( GL_ARRAY_BUFFER, 0, ctx->num_verts * sizeof( struct ui_vert ), ctx->verts );
+
+ glBindBuffer( GL_ELEMENT_ARRAY_BUFFER, ctx->ebo );
+ glBufferSubData( GL_ELEMENT_ARRAY_BUFFER, 0, ctx->num_indices * sizeof( u16 ), ctx->indices );
+
+ glEnable(GL_BLEND);
+ glBlendFunc(GL_SRC_ALPHA, GL_ONE_MINUS_SRC_ALPHA);
+ glBlendEquation(GL_FUNC_ADD);
+
+ SHADER_USE( shader_ui );
+
+ m3x3f view = M3X3_IDENTITY;
+
+ if( !view_override )
+ {
+ view_override = view;
+
+ m3x3_translate( view, (v3f){ -1.0f, 1.0f, 0.0f } );
+ m3x3_scale( view, (v3f){ 1.0f/((float)vg_window_x*0.5f), -1.0f/((float)vg_window_y*0.5f), 1.0f } );
+ }
+
+ glUniformMatrix3fv( SHADER_UNIFORM( shader_ui, "uPv" ), 1, GL_FALSE, (float *)view_override );
+
+ glActiveTexture( GL_TEXTURE0 );
+ glBindTexture( GL_TEXTURE_2D, ui_glyph_texture );
+ glUniform1i( SHADER_UNIFORM( shader_ui, "uTexGlyphs" ), 0 );
+
+ glDrawElements( GL_TRIANGLES, num_indices_normal, GL_UNSIGNED_SHORT, (void*)(0) );
+
+ // Draw image elements
+ for( int i = 0; i < ctx->image_count; i ++ )
+ {
+ struct ui_image *img = &ctx->images[i];
+
+ glBindTexture( GL_TEXTURE_2D, img->image );
+ glDrawElements( GL_TRIANGLES, 6, GL_UNSIGNED_SHORT, (void*)( (num_indices_normal + 6*i)*sizeof(u16) ) );
+ }
+
+ glDisable(GL_BLEND);
+}
+
+// Rect controls
+// ===========================================================================================================
+
+static void ui_rect_copy( ui_rect src, ui_rect dst )
+{
+ dst[0] = src[0];
+ dst[1] = src[1];
+ dst[2] = src[2];
+ dst[3] = src[3];
+}
+
+static void ui_rect_pad( ui_rect rect, ui_px pad )
+{
+ rect[0] += pad;
+ rect[1] += pad;
+ rect[2] -= pad*2;
+ rect[3] -= pad*2;
+}
+
+// Stack control
+// ===========================================================================================================
+
+static struct ui_qnode *ui_current( ui_ctx *ctx )
+{
+ return &ctx->stack[ ctx->stack_count-1 ];
+}
+
+static void ui_new_node( ui_ctx *ctx )
+{
+ if( ctx->stack_count == vg_list_size( ctx->stack ) )
+ vg_exiterr( "[UI] Stack overflow while creating box!" );
+
+ struct ui_qnode *parent = &ctx->stack[ ctx->stack_count-1 ];
+ struct ui_qnode *node = &ctx->stack[ ctx->stack_count++ ];
+ ui_rect_copy( ctx->cursor, node->rect );
+
+ if( parent->mouse_over )
+ {
+ if( ctx->mouse[0] >= node->rect[0] && ctx->mouse[0] < node->rect[0]+node->rect[2] &&
+ ctx->mouse[1] >= node->rect[1] && ctx->mouse[1] < node->rect[1]+node->rect[3] )
+ node->mouse_over = 1;
+ else
+ node->mouse_over = 0;
+ }
+ else
+ {
+ node->mouse_over = 0;
+ }
+}
+
+static int ui_hasmouse( ui_ctx *ctx )
+{
+ struct ui_qnode *node = ui_current( ctx );
+ return (node->mouse_over && (node->capture_id == ctx->capture_mouse_id));
+}
+
+static void ui_end( ui_ctx *ctx )
+{
+ struct ui_qnode *node = &ctx->stack[ --ctx->stack_count ];
+ ui_rect_copy( node->rect, ctx->cursor );
+}
+
+static void ui_end_down( ui_ctx *ctx )
+{
+ ui_px height = ui_current( ctx )->rect[3];
+ ui_end( ctx );
+ ctx->cursor[1] += height;
+}
+
+static void ui_end_right( ui_ctx *ctx )
+{
+ ui_px width = ui_current( ctx )->rect[2];
+ ui_end( ctx );
+ ctx->cursor[0] += width;
+}
+
+static void ui_fill_y( ui_ctx *ctx )
+{
+ struct ui_qnode *node = ui_current( ctx );
+ ctx->cursor[3] = node->rect[3] - (ctx->cursor[1]-node->rect[1]);
+}
+
+static void ui_fill_x( ui_ctx *ctx )
+{
+ struct ui_qnode *node = ui_current( ctx );
+ ctx->cursor[2] = node->rect[2] - (ctx->cursor[0]-node->rect[0]);
+}
+
+// Alignment: | [] | -> | []|
+static void ui_align_bottom( ui_ctx *ctx )
+{
+ struct ui_qnode *node = ui_current( ctx );
+ ctx->cursor[1] = node->rect[1] + node->rect[3] - ctx->cursor[3];
+}
+
+static void ui_align_right( ui_ctx *ctx )
+{
+ struct ui_qnode *node = ui_current( ctx );
+ ctx->cursor[0] = node->rect[0] + node->rect[2] - ctx->cursor[2];
+}
+
+static void ui_align_top( ui_ctx *ctx )
+{
+ ctx->cursor[1] = ui_current( ctx )->rect[1];
+}
+
+static void ui_align_left( ui_ctx *ctx )
+{
+ ctx->cursor[0] = ui_current( ctx )->rect[0];
+}
+
+static void ui_clamp_rect( ui_rect parent, ui_rect dest )
+{
+ dest[0] = vg_min( parent[0] + parent[2] - dest[2], dest[0] );
+ dest[1] = vg_min( parent[1] + parent[3] - dest[3], dest[1] );
+ dest[0] = vg_max( parent[0], dest[0] );
+ dest[1] = vg_max( parent[1], dest[1] );
+}
+
+static u32 ui_group_id( ui_ctx *ctx, u32 lesser_unique )
+{
+ return ctx->id_base | lesser_unique;
+}
+
+static void ui_capture_mouse( ui_ctx *ctx, u32 id )
+{
+ u32 group_uid = ui_group_id(ctx,id);
+
+ struct ui_qnode *node = &ctx->stack[ ctx->stack_count-1 ];
+ node->capture_id = group_uid;
+
+ if( !ctx->capture_lock && node->mouse_over )
+ {
+ ctx->capture_mouse_id = group_uid;
+ }
+}
+
+static int ui_want_mouse( ui_ctx *ctx )
+{
+ return ctx->capture_mouse_id == 0? 0: 1;
+}
+
+static void ui_set_clip( ui_ctx *ctx, ui_rect clip )
+{
+ ctx->clipping[0] = clip[0];
+ ctx->clipping[1] = clip[1];
+ ctx->clipping[2] = clip[0] + clip[2];
+ ctx->clipping[3] = clip[1] + clip[3];
+}
+
+static void ui_release_clip( ui_ctx *ctx )
+{
+ ctx->clipping[0] = -32000;
+ ctx->clipping[1] = -32000;
+ ctx->clipping[2] = 32000;
+ ctx->clipping[3] = 32000;
+}
+
+// Drawing
+// ===========================================================================================================
+
+static struct ui_vert *ui_fill_rect_uv( ui_ctx *ctx, ui_rect rect, u32 colour, ui_px uv[4] )
+{
+ struct ui_vert *vertices = &ctx->verts[ ctx->num_verts ];
+ vertices[0].co[0] = rect[0];
+ vertices[0].co[1] = rect[1];
+ vertices[0].uv[0] = uv[0];
+ vertices[0].uv[1] = uv[1];
+ vertices[0].colour = colour;
+ vertices[1].co[0] = rect[0]+rect[2];
+ vertices[1].co[1] = rect[1];
+ vertices[1].uv[0] = uv[2];
+ vertices[1].uv[1] = uv[1];
+ vertices[1].colour = colour;
+ vertices[2].co[0] = rect[0]+rect[2];
+ vertices[2].co[1] = rect[1]+rect[3];
+ vertices[2].uv[0] = uv[2];
+ vertices[2].uv[1] = uv[3];
+ vertices[2].colour = colour;
+ vertices[3].co[0] = rect[0];
+ vertices[3].co[1] = rect[1]+rect[3];
+ vertices[3].uv[0] = uv[0];
+ vertices[3].uv[1] = uv[3];
+ vertices[3].colour = colour;
+ u16 ind_start = ctx->num_verts;
+ u16 *indices = &ctx->indices[ ctx->num_indices ];
+
+ ui_rect_copy( ctx->clipping, vertices[0].clip );
+ ui_rect_copy( ctx->clipping, vertices[1].clip );
+ ui_rect_copy( ctx->clipping, vertices[2].clip );
+ ui_rect_copy( ctx->clipping, vertices[3].clip );
+
+ indices[0] = ind_start+0;
+ indices[1] = ind_start+2;
+ indices[2] = ind_start+1;
+
+ indices[3] = ind_start+0;
+ indices[4] = ind_start+3;
+ indices[5] = ind_start+2;
+
+ ctx->num_indices += 6;
+ ctx->num_verts += 4;
+
+ return vertices;
+}
+
+static struct ui_vert *ui_fill_rect( ui_ctx *ctx, ui_rect rect, u32 colour )
+{
+ return ui_fill_rect_uv( ctx, rect, colour, (ui_px[4]){ 4,4, 4,4 } );
+}
+
+static ui_px ui_text_line_offset( const char *str, ui_px scale, enum ui_text_align align )
+{
+ if( align == k_text_align_left )
+ return 0;
+
+ int length = 0;
+ const char *_c = str;
+ char c;
+
+ while( (c = *(_c ++)) )
+ if( c >= 32 && c <= 126 )
+ length ++;
+ else if( c == '\n' )
+ break;
+
+ if( align == k_text_align_right )
+ return -length * scale*8;
+ else
+ return (-length * scale*8) / 2;
+}
+
+static void ui_text( ui_ctx *ctx, ui_px pos[2], const char *str, ui_px scale, enum ui_text_align align )
+{
+ ui_rect text_cursor;
+ u32 current_colour = 0x00ffffff;
+
+ const char *_c = str;
+ u8 c;
+
+ text_cursor[0] = pos[0] + ui_text_line_offset( str, scale, align );
+ text_cursor[1] = pos[1];
+ text_cursor[2] = 8*scale;
+ text_cursor[3] = 14*scale;
+
+ while( (c = *(_c ++)) )
+ {
+ if( c == '\n' )
+ {
+ text_cursor[1] += 14*scale;
+ text_cursor[0] = pos[0] + ui_text_line_offset( _c, scale, align );
+ continue;
+ }
+ else if( c >= 33 )
+ {
+ u8 glyph_base[2];
+ u8 glyph_index = c;
+ glyph_base[0] = glyph_index & 0xf;
+ glyph_base[1] = (glyph_index-glyph_base[0])>>4;
+
+ glyph_base[0] *= 8;
+ glyph_base[1] *= 8;
+
+ ui_fill_rect_uv( ctx, text_cursor, current_colour, (ui_px[4]){glyph_base[0]+2,glyph_base[1]+1,glyph_base[0]+6,glyph_base[1]+8} );
+ }
+ else if( c == '\x1B' )
+ {
+ _c ++;
+ u16 colour_id = 0;
+ for( int i = 0; i < 3; i ++ )
+ {
+ if( _c[i] )
+ {
+ if( _c[i] == 'm' )
+ {
+ _c = _c + i + 1;
+
+ switch( colour_id )
+ {
+ case '0': current_colour = 0x00ffffff; break;
+ case '3'|'1'<<8: current_colour = 0x00201fee; break;
+ case '3'|'2'<<8: current_colour = 0x0037e420; break;
+ case '3'|'3'<<8: current_colour = 0x000ed8e2; break;
+ case '3'|'4'<<8: current_colour = 0x00f15010; break;
+ case '3'|'5'<<8: current_colour = 0x00ee20ee; break;
+ case '3'|'6'<<8: current_colour = 0x00eeee20; break;
+ case '3'|'7'<<8: current_colour = 0x00ffffff; break;
+ }
+
+ break;
+ }
+
+ colour_id |= _c[i] << (i*8);
+ }
+ else
+ {
+ _c = _c +i;
+ break;
+ }
+ }
+
+ continue;
+ }
+ else if( c == '\t' )
+ {
+ text_cursor[0] += UI_GLYPH_SPACING_X*scale*4;
+ continue;
+ }
+
+ text_cursor[0] += UI_GLYPH_SPACING_X*scale;
+ }
+}
+
+// API control
+// ====================================================================
+
+static void ui_begin( ui_ctx *ctx, ui_px res_x, ui_px res_y )
+{
+ ctx->cursor[0] = 0;
+ ctx->cursor[1] = 0;
+ ctx->cursor[2] = res_x;
+ ctx->cursor[3] = res_y;
+
+ ui_rect_copy( ctx->cursor, ctx->stack[0].rect );
+ ctx->stack[0].mouse_over = 1;
+
+ ctx->stack_count = 1;
+
+ ctx->num_verts = 0;
+ ctx->num_indices = 0;
+
+ ui_release_clip( ctx );
+
+ if( ctx->click_state == 0 )
+ ctx->capture_mouse_id = 0;
+
+ ctx->image_count = 0;
+}
+
+static void ui_resolve( ui_ctx *ctx )
+{
+ if( ctx->stack_count-1 )
+ vg_exiterr( "[UI] Mismatched node create/drestroy!" );
+
+ if( ctx->click_state == 3 || ctx->click_state == 0 )
+ {
+ ctx->capture_lock = 0;
+ }
+}
+
+// User Input piping
+// ====================================================================
+
+static void ui_set_mouse( ui_ctx *ctx, int x, int y, int click_state )
+{
+ ctx->mouse[0] = x;
+ ctx->mouse[1] = y;
+
+ ctx->click_state = click_state;
+}
+
+// High level controls
+// ====================================================================
+
+struct ui_window
+{
+ const char *title;
+ ui_rect transform;
+
+ int drag;
+ ui_px drag_offset[2];
+};
+
+enum button_state
+{
+ k_button_released = 0,
+ k_button_start_click,
+ k_button_click,
+ k_button_hold
+};
+
+static int ui_button( ui_ctx *ctx, u32 id )
+{
+ ui_new_node( ctx );
+ {
+ ui_capture_mouse( ctx, id );
+
+ if( ui_hasmouse(ctx) )
+ {
+ ui_fill_rect( ctx, ctx->cursor, ctx->colours->hover );
+
+ if( ctx->click_state == 1 )
+ {
+ ctx->capture_lock = 1;
+ return k_button_start_click;
+ }
+ else if( ctx->capture_lock && ctx->click_state == 3 )
+ return k_button_click;
+ else if( ctx->capture_lock && ctx->click_state == 2 )
+ return k_button_hold;
+ }
+ else
+ ui_fill_rect( ctx, ctx->cursor, ctx->colours->main );
+ }
+
+ return k_button_released;
+}
+
+static int ui_window( ui_ctx *ctx, struct ui_window *window, u32 control_group )
+{
+ ctx->id_base = control_group << 16;
+
+ if( window->drag )
+ {
+ window->transform[0] = ctx->mouse[0]+window->drag_offset[0];
+ window->transform[1] = ctx->mouse[1]+window->drag_offset[1];
+
+ ui_clamp_rect( ctx->stack[0].rect, window->transform );
+
+ if( ctx->click_state == 0 || ctx->click_state == 3 )
+ {
+ window->drag = 0;
+ }
+ }
+
+ ui_rect_copy( window->transform, ctx->cursor );
+
+ ui_new_node( ctx );
+ {
+ ui_capture_mouse( ctx, __COUNTER__ );
+
+ // Drag bar
+ ctx->cursor[3] = 25;
+ ui_new_node( ctx );
+ {
+ ui_capture_mouse( ctx, __COUNTER__ );
+
+ struct ui_vert *drag_bar = ui_fill_rect( ctx, ctx->cursor, 0xff555555 );
+
+ // title..
+ ctx->cursor[0] += 2;
+ ctx->cursor[1] += 2;
+ ui_text( ctx, ctx->cursor, window->title, 2, 0 );
+
+ // Close button
+ ctx->cursor[3] = 25;
+ ctx->cursor[2] = 25;
+ ui_align_right( ctx );
+ ui_align_top( ctx );
+ ui_rect_pad( ctx->cursor, 4 );
+
+ if( ui_button( ctx, __COUNTER__ ) )
+ {
+ vg_info( "Click clacked\n" );
+ }
+ ctx->cursor[0] += 2;
+ ui_text( ctx, ctx->cursor, "x", 2, 0 );
+ ui_end( ctx );
+
+ if( ui_hasmouse( ctx ) )
+ {
+ drag_bar[0].colour = 0xff777777;
+ drag_bar[1].colour = 0xff777777;
+ drag_bar[2].colour = 0xff777777;
+ drag_bar[3].colour = 0xff777777;
+
+ // start drag
+ if( ctx->click_state == 1 )
+ {
+ window->drag = 1;
+ window->drag_offset[0] = window->transform[0]-ctx->mouse[0];
+ window->drag_offset[1] = window->transform[1]-ctx->mouse[1];
+ }
+ }
+ }
+ ui_end_down( ctx );
+ }
+
+ return 1;
+}
+
+struct ui_scrollbar
+{
+ int drag;
+ ui_px drag_offset;
+
+ ui_px py;
+ ui_px bar_height;
+ ui_px view_height;
+};
+
+static void ui_scrollbar( ui_ctx *ctx, struct ui_scrollbar *scrollbar, u32 id )
+{
+ scrollbar->view_height = ctx->cursor[3];
+
+ if( scrollbar->drag )
+ {
+ scrollbar->py = ctx->mouse[1]+scrollbar->drag_offset;
+ scrollbar->py = VG_MAX( scrollbar->py, 0 );
+ scrollbar->py = VG_MIN( scrollbar->py, ctx->cursor[3] - scrollbar->bar_height );
+
+ if( ctx->click_state == 0 || ctx->click_state == 3 )
+ scrollbar->drag = 0;
+ }
+
+ ui_new_node( ctx );
+ {
+ ui_fill_rect( ctx, ctx->cursor, ctx->colours->background );
+ ui_capture_mouse( ctx, id );
+
+ ctx->cursor[1] += scrollbar->py;
+ ctx->cursor[3] = scrollbar->bar_height;
+
+ ui_new_node( ctx );
+ {
+ ui_capture_mouse( ctx, __COUNTER__ );
+ struct ui_vert *drag_bar = ui_fill_rect( ctx, ctx->cursor, ctx->colours->bar );
+
+ if( ui_hasmouse( ctx ) || scrollbar->drag )
+ {
+ drag_bar[0].colour = ctx->colours->bar_hover;
+ drag_bar[1].colour = ctx->colours->bar_hover;
+ drag_bar[2].colour = ctx->colours->bar_hover;
+ drag_bar[3].colour = ctx->colours->bar_hover;
+
+ // start drag
+ if( ctx->click_state == 1 )
+ {
+ scrollbar->drag = 1;
+ scrollbar->drag_offset = scrollbar->py - ctx->mouse[1];
+ }
+ }
+ }
+ ui_end_down( ctx );
+ }
+ ui_end( ctx );
+}
+
+static ui_px ui_calculate_content_scroll( struct ui_scrollbar *scrollbar, ui_px content )
+{
+ float overlap = vg_maxf( 0.0f, (float)(content - scrollbar->view_height) );
+
+ float range = scrollbar->view_height - scrollbar->bar_height;
+ return ((float)scrollbar->py / range) * overlap;
+}
+
+static void ui_push_image( ui_ctx *ctx, ui_rect rc, GLuint image )
+{
+ struct ui_image *img = &ctx->images[ ctx->image_count ++ ];
+ ui_rect_copy( rc, img->rc );
+ img->image = image;
+}
+
+// Shortnames
+#define gui_draw(...) ui_draw( &ui_global_ctx, __VA_ARGS__)
+#define gui_current(...) ui_current( &ui_global_ctx, __VA_ARGS__)
+#define gui_new_node() ui_new_node( &ui_global_ctx )
+#define gui_hasmouse(...) ui_hasmouse( &ui_global_ctx, __VA_ARGS__)
+#define gui_end() ui_end( &ui_global_ctx )
+#define gui_end_down() ui_end_down( &ui_global_ctx )
+#define gui_end_right() ui_end_right( &ui_global_ctx )
+#define gui_fill_y() ui_fill_y( &ui_global_ctx)
+#define gui_fill_x() ui_fill_x( &ui_global_ctx)
+#define gui_align_bottom() ui_align_bottom( &ui_global_ctx )
+#define gui_align_right() ui_align_right( &ui_global_ctx )
+#define gui_align_top() ui_align_top( &ui_global_ctx )
+#define gui_align_left() ui_align_left( &ui_global_ctx )
+#define gui_clamp_rect(...) ui_clamp_rect( &ui_global_ctx, __VA_ARGS__)
+#define gui_group_id(...) ui_group_id( &ui_global_ctx, __VA_ARGS__)
+#define gui_capture_mouse(...) ui_capture_mouse( &ui_global_ctx, __VA_ARGS__)
+#define gui_set_clip(...) ui_set_clip( &ui_global_ctx, __VA_ARGS__)
+#define gui_release_clip() ui_release_clip( &ui_global_ctx )
+#define gui_fill_rect_uv(...) ui_fill_rect_uv( &ui_global_ctx, __VA_ARGS__)
+#define gui_fill_rect(...) ui_fill_rect( &ui_global_ctx, __VA_ARGS__)
+#define gui_text(...) ui_text( &ui_global_ctx, __VA_ARGS__)
+#define gui_begin(...) ui_begin( &ui_global_ctx, __VA_ARGS__)
+#define gui_resolve(...) ui_resolve( &ui_global_ctx, __VA_ARGS__)
+#define gui_set_mouse(...) ui_set_mouse( &ui_global_ctx, __VA_ARGS__)
+#define gui_button(...) ui_button( &ui_global_ctx, __VA_ARGS__)
+#define gui_window(...) ui_window( &ui_global_ctx, __VA_ARGS__)
+#define gui_want_mouse() ui_want_mouse( &ui_global_ctx )
+#define gui_push_image(...) ui_push_image( &ui_global_ctx, __VA_ARGS__ )
+#define gui_scrollbar(...) ui_scrollbar( &ui_global_ctx, __VA_ARGS__)
+#define gui_reset_colours(...) ui_reset_colours( &ui_global_ctx )