OpenGL: shaders for smooth round points

Solid color with an optional outline.

size (diameter) and outlineWidth are in pixels.

source/blender/gpu/CMakeLists.txt

@@ -136,11 +136,15 @@ data_to_c_simple(shaders/gpu_shader_3D_smooth_color_vert.glsl SRC)
 data_to_c_simple(shaders/gpu_shader_3D_smooth_color_frag.glsl SRC)
 
 data_to_c_simple(shaders/gpu_shader_point_uniform_color_frag.glsl SRC)
+data_to_c_simple(shaders/gpu_shader_point_uniform_color_smooth_frag.glsl SRC)
+data_to_c_simple(shaders/gpu_shader_point_uniform_color_outline_smooth_frag.glsl SRC)
 data_to_c_simple(shaders/gpu_shader_point_varying_color_frag.glsl SRC)
 data_to_c_simple(shaders/gpu_shader_3D_point_fixed_size_varying_color_vert.glsl SRC)
 data_to_c_simple(shaders/gpu_shader_3D_point_varying_size_no_color_vert.glsl SRC)
 data_to_c_simple(shaders/gpu_shader_3D_point_varying_size_varying_color_vert.glsl SRC)
 data_to_c_simple(shaders/gpu_shader_2D_point_varying_size_varying_color_vert.glsl SRC)
+data_to_c_simple(shaders/gpu_shader_2D_point_uniform_size_uniform_color_smooth_vert.glsl SRC)
+data_to_c_simple(shaders/gpu_shader_2D_point_uniform_size_uniform_color_outline_smooth_vert.glsl SRC)
 
 data_to_c_simple(shaders/gpu_shader_text_vert.glsl SRC)
 data_to_c_simple(shaders/gpu_shader_text_frag.glsl SRC)

source/blender/gpu/GPU_shader.h

@@ -106,6 +106,8 @@ typedef enum GPUBuiltinShader {
 	GPU_SHADER_2D_TEXTURE_RECT,
 	/* points */
 	GPU_SHADER_2D_POINT_FIXED_SIZE_UNIFORM_COLOR,
+	GPU_SHADER_2D_POINT_UNIFORM_SIZE_UNIFORM_COLOR_SMOOTH,
+	GPU_SHADER_2D_POINT_UNIFORM_SIZE_UNIFORM_COLOR_OUTLINE_SMOOTH,
 	GPU_SHADER_2D_POINT_VARYING_SIZE_VARYING_COLOR,
 	GPU_SHADER_3D_POINT_FIXED_SIZE_UNIFORM_COLOR,
 	GPU_SHADER_3D_POINT_FIXED_SIZE_VARYING_COLOR,

source/blender/gpu/intern/gpu_shader.c

@@ -62,11 +62,15 @@ extern char datatoc_gpu_shader_3D_smooth_color_vert_glsl[];
 extern char datatoc_gpu_shader_3D_smooth_color_frag_glsl[];
 
 extern char datatoc_gpu_shader_point_uniform_color_frag_glsl[];
+extern char datatoc_gpu_shader_point_uniform_color_smooth_frag_glsl[];
+extern char datatoc_gpu_shader_point_uniform_color_outline_smooth_frag_glsl[];
 extern char datatoc_gpu_shader_point_varying_color_frag_glsl[];
 extern char datatoc_gpu_shader_3D_point_fixed_size_varying_color_vert_glsl[];
 extern char datatoc_gpu_shader_3D_point_varying_size_no_color_vert_glsl[];
 extern char datatoc_gpu_shader_3D_point_varying_size_varying_color_vert_glsl[];
 extern char datatoc_gpu_shader_2D_point_varying_size_varying_color_vert_glsl[];
+extern char datatoc_gpu_shader_2D_point_uniform_size_uniform_color_smooth_vert_glsl[];
+extern char datatoc_gpu_shader_2D_point_uniform_size_uniform_color_outline_smooth_vert_glsl[];
 
 extern char datatoc_gpu_shader_text_vert_glsl[];
 extern char datatoc_gpu_shader_text_frag_glsl[];
@@ -113,6 +117,8 @@ static struct GPUShadersGlobal {
 		/* points */
 		GPUShader *point_fixed_size_uniform_color_2D;
 		GPUShader *point_varying_size_varying_color_2D;
+		GPUShader *point_uniform_size_uniform_color_smooth_2D;
+		GPUShader *point_uniform_size_uniform_color_outline_smooth_2D;
 		GPUShader *point_fixed_size_uniform_color_3D;
 		GPUShader *point_fixed_size_varying_color_3D;
 		GPUShader *point_varying_size_uniform_color_3D;
@@ -739,6 +745,22 @@ GPUShader *GPU_shader_get_builtin_shader(GPUBuiltinShader shader)
 				        NULL, NULL, NULL, 0, 0, 0);
 			retval = GG.shaders.point_varying_size_varying_color_2D;
 			break;
+		case GPU_SHADER_2D_POINT_UNIFORM_SIZE_UNIFORM_COLOR_SMOOTH:
+			if (!GG.shaders.point_uniform_size_uniform_color_smooth_2D)
+				GG.shaders.point_uniform_size_uniform_color_smooth_2D = GPU_shader_create(
+				        datatoc_gpu_shader_2D_point_uniform_size_uniform_color_smooth_vert_glsl,
+				        datatoc_gpu_shader_point_uniform_color_smooth_frag_glsl,
+				        NULL, NULL, NULL, 0, 0, 0);
+			retval = GG.shaders.point_uniform_size_uniform_color_smooth_2D;
+			break;
+		case GPU_SHADER_2D_POINT_UNIFORM_SIZE_UNIFORM_COLOR_OUTLINE_SMOOTH:
+			if (!GG.shaders.point_uniform_size_uniform_color_outline_smooth_2D)
+				GG.shaders.point_uniform_size_uniform_color_outline_smooth_2D = GPU_shader_create(
+				        datatoc_gpu_shader_2D_point_uniform_size_uniform_color_outline_smooth_vert_glsl,
+				        datatoc_gpu_shader_point_uniform_color_outline_smooth_frag_glsl,
+				        NULL, NULL, NULL, 0, 0, 0);
+			retval = GG.shaders.point_uniform_size_uniform_color_outline_smooth_2D;
+			break;
 		case GPU_SHADER_3D_POINT_FIXED_SIZE_UNIFORM_COLOR:
 			if (!GG.shaders.point_fixed_size_uniform_color_3D)
 				GG.shaders.point_fixed_size_uniform_color_3D = GPU_shader_create(
@@ -935,6 +957,16 @@ void GPU_shader_free_builtin_shaders(void)
 		GG.shaders.point_varying_size_varying_color_2D = NULL;
 	}
 
+	if (GG.shaders.point_uniform_size_uniform_color_smooth_2D) {
+		GPU_shader_free(GG.shaders.point_uniform_size_uniform_color_smooth_2D);
+		GG.shaders.point_uniform_size_uniform_color_smooth_2D = NULL;
+	}
+
+	if (GG.shaders.point_uniform_size_uniform_color_outline_smooth_2D) {
+		GPU_shader_free(GG.shaders.point_uniform_size_uniform_color_outline_smooth_2D);
+		GG.shaders.point_uniform_size_uniform_color_outline_smooth_2D = NULL;
+	}
+
 	if (GG.shaders.point_fixed_size_uniform_color_3D) {
 		GPU_shader_free(GG.shaders.point_fixed_size_uniform_color_3D);
 		GG.shaders.point_fixed_size_uniform_color_3D = NULL;

source/blender/gpu/shaders/gpu_shader_2D_point_uniform_size_uniform_color_outline_smooth_vert.glsl

@@ -0,0 +1,28 @@
+
+uniform float size;
+uniform float outlineWidth;
+
+#if __VERSION__ == 120
+  attribute vec2 pos;
+  varying vec4 radii;
+#else
+  in vec2 pos;
+  out vec4 radii;
+#endif
+
+void main() {
+	gl_Position = gl_ModelViewProjectionMatrix * vec4(pos, 0.0, 1.0);
+	gl_PointSize = size;
+
+	// calculate concentric radii in pixels
+	float radius = 0.5 * size;
+
+	// start at the outside and progress toward the center
+	radii[0] = radius;
+	radii[1] = radius - 1.0;
+	radii[2] = radius - outlineWidth;
+	radii[3] = radius - outlineWidth - 1.0;
+
+	// convert to PointCoord units
+	radii /= size;
+}

source/blender/gpu/shaders/gpu_shader_2D_point_uniform_size_uniform_color_smooth_vert.glsl

@@ -0,0 +1,25 @@
+
+uniform float size;
+
+#if __VERSION__ == 120
+  attribute vec2 pos;
+  varying vec2 radii;
+#else
+  in vec2 pos;
+  out vec2 radii;
+#endif
+
+void main() {
+	gl_Position = gl_ModelViewProjectionMatrix * vec4(pos, 0.0, 1.0);
+	gl_PointSize = size;
+
+	// calculate concentric radii in pixels
+	float radius = 0.5 * size;
+
+	// start at the outside and progress toward the center
+	radii[0] = radius;
+	radii[1] = radius - 1.0;
+
+	// convert to PointCoord units
+	radii /= size;
+}

source/blender/gpu/shaders/gpu_shader_point_uniform_color_outline_smooth_frag.glsl

@@ -0,0 +1,34 @@
+
+uniform vec4 color;
+uniform vec4 outlineColor;
+
+#if __VERSION__ == 120
+  varying vec4 radii;
+  #define fragColor gl_FragColor
+#else
+  in vec4 radii;
+  out vec4 fragColor;
+#endif
+
+void main() {
+	float dist = length(gl_PointCoord - vec2(0.5));
+
+// transparent outside of point
+// --- 0 ---
+// smooth transition
+// --- 1 ---
+// pure outline color
+// --- 2 ---
+// smooth transition
+// --- 3 ---
+// pure point color
+// ...
+// dist = 0 at center of point
+
+	float midStroke = 0.5 * (radii[1] + radii[2]);
+
+	if (dist > midStroke)
+		fragColor = mix(outlineColor, vec4(0.0), smoothstep(radii[1], radii[0], dist));
+	else
+		fragColor = mix(color, outlineColor, smoothstep(radii[3], radii[2], dist));
+}

source/blender/gpu/shaders/gpu_shader_point_uniform_color_smooth_frag.glsl

@@ -0,0 +1,24 @@
+
+uniform vec4 color;
+
+#if __VERSION__ == 120
+  varying vec2 radii;
+  #define fragColor gl_FragColor
+#else
+  in vec2 radii;
+  out vec4 fragColor;
+#endif
+
+void main() {
+	float dist = length(gl_PointCoord - vec2(0.5));
+
+// transparent outside of point
+// --- 0 ---
+//	smooth transition
+// --- 1 ---
+// pure point color
+// ...
+// dist = 0 at center of point
+
+	fragColor = mix(color, vec4(0.0), smoothstep(radii[1], radii[0], dist));
+}