render/gles2: transpose matrices before binding them

Setting glUniformMatrix3fv's transpose parameter to GL_TRUE is
not allowed for OpenGL ES 2.

This adds a wlr_matrix_transpose function.

1 files changed, 18 insertions, 3 deletions

diff --git a/render/gles2/renderer.c b/render/gles2/renderer.c
index a212e908..8d8dd17f 100644
--- a/render/gles2/renderer.c
+++ b/render/gles2/renderer.c
@@ -180,8 +180,13 @@ static bool wlr_gles2_render_texture_with_matrix(
 		return false;
 	}
 
+	// OpenGL ES 2 requires the glUniformMatrix3fv transpose parameter to be set
+	// to GL_FALSE
+	float transposition[9];
+	wlr_matrix_transpose(transposition, matrix);
+
 	wlr_texture_bind(texture);
-	GL_CALL(glUniformMatrix3fv(0, 1, GL_TRUE, matrix));
+	GL_CALL(glUniformMatrix3fv(0, 1, GL_FALSE, transposition));
 	GL_CALL(glUniform1i(1, texture->inverted_y));
 	GL_CALL(glUniform1f(3, alpha));
 	draw_quad();
@@ -191,16 +196,26 @@ static bool wlr_gles2_render_texture_with_matrix(
 
 static void wlr_gles2_render_quad(struct wlr_renderer *wlr_renderer,
 		const float color[static 4], const float matrix[static 9]) {
+	// OpenGL ES 2 requires the glUniformMatrix3fv transpose parameter to be set
+	// to GL_FALSE
+	float transposition[9];
+	wlr_matrix_transpose(transposition, matrix);
+
 	GL_CALL(glUseProgram(shaders.quad));
-	GL_CALL(glUniformMatrix3fv(0, 1, GL_TRUE, matrix));
+	GL_CALL(glUniformMatrix3fv(0, 1, GL_FALSE, transposition));
 	GL_CALL(glUniform4f(1, color[0], color[1], color[2], color[3]));
 	draw_quad();
 }
 
 static void wlr_gles2_render_ellipse(struct wlr_renderer *wlr_renderer,
 		const float color[static 4], const float matrix[static 9]) {
+	// OpenGL ES 2 requires the glUniformMatrix3fv transpose parameter to be set
+	// to GL_FALSE
+	float transposition[9];
+	wlr_matrix_transpose(transposition, matrix);
+
 	GL_CALL(glUseProgram(shaders.ellipse));
-	GL_CALL(glUniformMatrix3fv(0, 1, GL_TRUE, matrix));
+	GL_CALL(glUniformMatrix3fv(0, 1, GL_FALSE, transposition));
 	GL_CALL(glUniform4f(1, color[0], color[1], color[2], color[3]));
 	draw_quad();
 }