Add alpha to wlr_render_with_matrix

so we can use the alpha channel to e.g. blend in textures

backend/drm/drm.c

@@ -647,7 +647,7 @@ static bool wlr_drm_connector_set_cursor(struct wlr_output *output,
 	float matrix[16];
 	wlr_texture_get_matrix(plane->wlr_tex, &matrix, &plane->matrix, 0, 0);
 	wlr_render_with_matrix(plane->surf.renderer->wlr_rend, plane->wlr_tex,
-		&matrix);
+		&matrix, 1.0f);
 
 	glFinish();
 	glPixelStorei(GL_UNPACK_ROW_LENGTH_EXT, bo_stride);

backend/drm/renderer.c

@@ -239,7 +239,7 @@ struct gbm_bo *wlr_drm_surface_mgpu_copy(struct wlr_drm_surface *dest,
 	glViewport(0, 0, dest->width, dest->height);
 	glClearColor(0.0, 0.0, 0.0, 1.0);
 	glClear(GL_COLOR_BUFFER_BIT);
-	wlr_render_with_matrix(dest->renderer->wlr_rend, tex, &matrix);
+	wlr_render_with_matrix(dest->renderer->wlr_rend, tex, &matrix, 1.0f);
 
 	return wlr_drm_surface_swap_buffers(dest, NULL);
 }

examples/output-layout.c

@@ -122,7 +122,7 @@ static void handle_output_frame(struct output_state *output,
 		wlr_texture_get_matrix(sample->cat_texture, &matrix,
 			&wlr_output->transform_matrix, local_x, local_y);
 		wlr_render_with_matrix(sample->renderer,
-			sample->cat_texture, &matrix);
+			sample->cat_texture, &matrix, 1.0f);
 	}
 
 	wlr_renderer_end(sample->renderer);

examples/rotation.c

@@ -52,7 +52,7 @@ static void handle_output_frame(struct output_state *output, struct timespec *ts
 			wlr_texture_get_matrix(sample->cat_texture, &matrix,
 				&wlr_output->transform_matrix, x, y);
 			wlr_render_with_matrix(sample->renderer,
-					sample->cat_texture, &matrix);
+					sample->cat_texture, &matrix, 1.0f);
 		}
 	}
 

examples/touch.c

@@ -53,7 +53,7 @@ static void handle_output_frame(struct output_state *output, struct timespec *ts
 			(int)(p->x * width) - sample->cat_texture->width / 2,
 			(int)(p->y * height) - sample->cat_texture->height / 2);
 		wlr_render_with_matrix(sample->renderer,
-			sample->cat_texture, &matrix);
+			sample->cat_texture, &matrix, 1.0f);
 	}
 
 	wlr_renderer_end(sample->renderer);

include/wlr/render.h

@@ -33,12 +33,13 @@ struct wlr_texture *wlr_render_texture_create(struct wlr_renderer *r);
  * 	float projection[16];
  * 	float matrix[16];
  * 	wlr_texture_get_matrix(texture, &matrix, &projection, 123, 321);
- * 	wlr_render_with_matrix(renderer, texture, &matrix);
+ * 	wlr_render_with_matrix(renderer, texture, &matrix, 0.5f);
  *
- * This will render the texture at <123, 321>.
+ * This will render the texture at <123, 321> with an alpha channel of 0.5.
  */
 bool wlr_render_with_matrix(struct wlr_renderer *r,
-	struct wlr_texture *texture, const float (*matrix)[16]);
+	struct wlr_texture *texture, const float (*matrix)[16], float alpha);
+
 /**
  * Renders a solid quad in the specified color.
  */

include/wlr/render/interface.h

@@ -22,7 +22,7 @@ struct wlr_renderer_impl {
 	void (*scissor)(struct wlr_renderer *renderer, struct wlr_box *box);
 	struct wlr_texture *(*texture_create)(struct wlr_renderer *renderer);
 	bool (*render_with_matrix)(struct wlr_renderer *renderer,
-		struct wlr_texture *texture, const float (*matrix)[16]);
+		struct wlr_texture *texture, const float (*matrix)[16], float alpha);
 	void (*render_quad)(struct wlr_renderer *renderer,
 		const float (*color)[4], const float (*matrix)[16]);
 	void (*render_ellipse)(struct wlr_renderer *renderer,

render/gles2/renderer.c

@@ -171,7 +171,7 @@ static void draw_quad() {
 }
 
 static bool wlr_gles2_render_texture(struct wlr_renderer *wlr_renderer,
-		struct wlr_texture *texture, const float (*matrix)[16]) {
+		struct wlr_texture *texture, const float (*matrix)[16], float alpha) {
 	if (!texture || !texture->valid) {
 		wlr_log(L_ERROR, "attempt to render invalid texture");
 		return false;
@@ -179,12 +179,12 @@ static bool wlr_gles2_render_texture(struct wlr_renderer *wlr_renderer,
 
 	wlr_texture_bind(texture);
 	GL_CALL(glUniformMatrix4fv(0, 1, GL_FALSE, *matrix));
-	// TODO: source alpha from somewhere else I guess
+	GL_CALL(glUniform1f(2, alpha));
-	GL_CALL(glUniform1f(2, 1.0f));
 	draw_quad();
 	return true;
 }
 
+
 static void wlr_gles2_render_quad(struct wlr_renderer *wlr_renderer,
 		const float (*color)[4], const float (*matrix)[16]) {
 	GL_CALL(glUseProgram(shaders.quad));

render/wlr_renderer.c

@@ -36,8 +36,8 @@ struct wlr_texture *wlr_render_texture_create(struct wlr_renderer *r) {
 }
 
 bool wlr_render_with_matrix(struct wlr_renderer *r,
-		struct wlr_texture *texture, const float (*matrix)[16]) {
+		struct wlr_texture *texture, const float (*matrix)[16], float alpha) {
-	return r->impl->render_with_matrix(r, texture, matrix);
+	return r->impl->render_with_matrix(r, texture, matrix, alpha);
 }
 
 void wlr_render_colored_quad(struct wlr_renderer *r,

rootston/output.c

@@ -296,7 +296,7 @@ static void render_surface(struct wlr_surface *surface, double lx, double ly,
 	pixman_box32_t *rects = pixman_region32_rectangles(&damage, &nrects);
 	for (int i = 0; i < nrects; ++i) {
 		scissor_output(output, &rects[i]);
-		wlr_render_with_matrix(renderer, surface->texture, &matrix);
+		wlr_render_with_matrix(renderer, surface->texture, &matrix, 1.0f);
 	}
 
 damage_finish:

types/wlr_output.c

@@ -391,7 +391,7 @@ static void output_fullscreen_surface_render(struct wlr_output *output,
 	for (int i = 0; i < nrects; ++i) {
 		output_scissor(output, &rects[i]);
 		wlr_renderer_clear(renderer, &(float[]){0, 0, 0, 0});
-		wlr_render_with_matrix(surface->renderer, surface->texture, &matrix);
+		wlr_render_with_matrix(surface->renderer, surface->texture, &matrix, 1.0f);
 	}
 	wlr_renderer_scissor(renderer, NULL);
 
@@ -448,7 +448,7 @@ static void output_cursor_render(struct wlr_output_cursor *cursor,
 	pixman_box32_t *rects = pixman_region32_rectangles(&surface_damage, &nrects);
 	for (int i = 0; i < nrects; ++i) {
 		output_scissor(cursor->output, &rects[i]);
-		wlr_render_with_matrix(renderer, texture, &matrix);
+		wlr_render_with_matrix(renderer, texture, &matrix, 1.0f);
 	}
 	wlr_renderer_scissor(renderer, NULL);