BLF/OpenGL: more text drawing optimization

Make color values compact. Set color once per primitive. Use new immSkipAttrib to avoid useless color copies.

All of this should make text drawing less CPU hungry.

1 files changed, 30 insertions, 27 deletions

diff --git a/source/blender/blenfont/intern/blf_glyph.c b/source/blender/blenfont/intern/blf_glyph.c
index 746aa722c4a..b1bab13f3ae 100644
--- a/source/blender/blenfont/intern/blf_glyph.c
+++ b/source/blender/blenfont/intern/blf_glyph.c
@@ -315,22 +315,26 @@ void blf_glyph_free(GlyphBLF *g)
 	MEM_freeN(g);
 }
 
-static void blf_texture_draw(float uv[2][2], float dx, float y1, float dx1, float y2)
+static void blf_texture_draw(const unsigned char color[4], float uv[2][2], float dx, float y1, float dx1, float y2)
 {
 	immAttrib2f(BLF_COORD_ID, uv[0][0], uv[0][1]);
+	immSkipAttrib(BLF_COLOR_ID); /* skip color of most vertices */
 	immVertex2f(BLF_POS_ID, dx, y1);
 
 	immAttrib2f(BLF_COORD_ID, uv[0][0], uv[1][1]);
+	immSkipAttrib(BLF_COLOR_ID);
 	immVertex2f(BLF_POS_ID, dx, y2);
 
 	immAttrib2f(BLF_COORD_ID, uv[1][0], uv[1][1]);
+	immSkipAttrib(BLF_COLOR_ID);
 	immVertex2f(BLF_POS_ID, dx1, y2);
 
 	immAttrib2f(BLF_COORD_ID, uv[1][0], uv[0][1]);
+	immAttrib4ubv(BLF_COLOR_ID, color); /* set color of provoking vertex */
 	immVertex2f(BLF_POS_ID, dx1, y1);
 }
 
-static void blf_texture5_draw(const float shadow_col[4], float uv[2][2], float x1, float y1, float x2, float y2)
+static void blf_texture5_draw(const unsigned char color_in[4], float uv[2][2], float x1, float y1, float x2, float y2)
 {
 	const float soft[25] = {1 / 60.0f, 1 / 60.0f, 2 / 60.0f, 1 / 60.0f, 1 / 60.0f,
 	                        1 / 60.0f, 3 / 60.0f, 5 / 60.0f, 3 / 60.0f, 1 / 60.0f,
@@ -339,41 +343,43 @@ static void blf_texture5_draw(const float shadow_col[4], float uv[2][2], float x
 	                        1 / 60.0f, 1 / 60.0f, 2 / 60.0f, 1 / 60.0f, 1 / 60.0f};
 
 	const float *fp = soft;
-	float color[4];
+	unsigned char color[4];
 	float dx, dy;
 
-	color[0] = shadow_col[0];
-	color[1] = shadow_col[1];
-	color[2] = shadow_col[2];
+	color[0] = color_in[0];
+	color[1] = color_in[1];
+	color[2] = color_in[2];
+
+	const float alpha_in = (1 / 255.0f) * color_in[3];
 
 	for (dx = -2; dx < 3; dx++) {
 		for (dy = -2; dy < 3; dy++, fp++) {
-			color[3] = *(fp) * shadow_col[3];
-			immAttrib4fv(BLF_COLOR_ID, color);
-			blf_texture_draw(uv, x1 + dx, y1 + dy, x2 + dx, y2 + dy);
+			color[3] = FTOCHAR(*fp * alpha_in);
+			blf_texture_draw(color, uv, x1 + dx, y1 + dy, x2 + dx, y2 + dy);
 		}
 	}
 }
 
-static void blf_texture3_draw(const float shadow_col[4], float uv[2][2], float x1, float y1, float x2, float y2)
+static void blf_texture3_draw(const unsigned char color_in[4], float uv[2][2], float x1, float y1, float x2, float y2)
 {
 	const float soft[9] = {1 / 16.0f, 2 / 16.0f, 1 / 16.0f,
 	                       2 / 16.0f, 4 / 16.0f, 2 / 16.0f,
 	                       1 / 16.0f, 2 / 16.0f, 1 / 16.0f};
 
 	const float *fp = soft;
-	float color[4];
+	unsigned char color[4];
 	float dx, dy;
 
-	color[0] = shadow_col[0];
-	color[1] = shadow_col[1];
-	color[2] = shadow_col[2];
+	color[0] = color_in[0];
+	color[1] = color_in[1];
+	color[2] = color_in[2];
+
+	const float alpha_in = (1 / 255.0f) * color_in[3];
 
 	for (dx = -1; dx < 2; dx++) {
 		for (dy = -1; dy < 2; dy++, fp++) {
-			color[3] = *(fp) * shadow_col[3];
-			immAttrib4fv(BLF_COLOR_ID, color);
-			blf_texture_draw(uv, x1 + dx, y1 + dy, x2 + dx, y2 + dy);
+			color[3] = FTOCHAR(*fp * alpha_in);
+			blf_texture_draw(color, uv, x1 + dx, y1 + dy, x2 + dx, y2 + dy);
 		}
 	}
 }
@@ -478,31 +484,28 @@ void blf_glyph_render(FontBLF *font, GlyphBLF *g, float x, float y)
 		                    y + (float)font->shadow_y);
 
 		if (font->shadow == 0) {
-			immAttrib4fv(BLF_COLOR_ID, font->shadow_col);
-			blf_texture_draw(g->uv, rect_ofs.xmin, rect_ofs.ymin, rect_ofs.xmax, rect_ofs.ymax);
+			blf_texture_draw(font->shadow_color, g->uv, rect_ofs.xmin, rect_ofs.ymin, rect_ofs.xmax, rect_ofs.ymax);
 		}
 		else if (font->shadow <= 4) {
-			blf_texture3_draw(font->shadow_col, g->uv, rect_ofs.xmin, rect_ofs.ymin, rect_ofs.xmax, rect_ofs.ymax);
+			blf_texture3_draw(font->shadow_color, g->uv, rect_ofs.xmin, rect_ofs.ymin, rect_ofs.xmax, rect_ofs.ymax);
 		}
 		else {
-			blf_texture5_draw(font->shadow_col, g->uv, rect_ofs.xmin, rect_ofs.ymin, rect_ofs.xmax, rect_ofs.ymax);
+			blf_texture5_draw(font->shadow_color, g->uv, rect_ofs.xmin, rect_ofs.ymin, rect_ofs.xmax, rect_ofs.ymax);
 		}
 	}
 
 #if BLF_BLUR_ENABLE
 	switch (font->blur) {
 		case 3:
-			blf_texture3_draw(font->orig_col, g->uv, rect.xmin, rect.ymin, rect.xmax, rect.ymax);
+			blf_texture3_draw(font->color, g->uv, rect.xmin, rect.ymin, rect.xmax, rect.ymax);
 			break;
 		case 5:
-			blf_texture5_draw(font->orig_col, g->uv, rect.xmin, rect.ymin, rect.xmax, rect.ymax);
+			blf_texture5_draw(font->color, g->uv, rect.xmin, rect.ymin, rect.xmax, rect.ymax);
 			break;
 		default:
-			immAttrib4fv(BLF_COLOR_ID, font->orig_col);
-			blf_texture_draw(g->uv, rect.xmin, rect.ymin, rect.xmax, rect.ymax);
+			blf_texture_draw(font->color, g->uv, rect.xmin, rect.ymin, rect.xmax, rect.ymax);
 	}
 #else
-	immAttrib4fv(BLF_COLOR_ID, font->orig_col);
-	blf_texture_draw(g->uv, rect.xmin, rect.ymin, rect.xmax, rect.ymax);
+	blf_texture_draw(font->color, g->uv, rect.xmin, rect.ymin, rect.xmax, rect.ymax);
 #endif
 }