Switch to GLES2

Closes #13

5 files changed, 70 insertions, 84 deletions

diff --git a/render/CMakeLists.txt b/render/CMakeLists.txt
index 7b863d64..70ebced2 100644
--- a/render/CMakeLists.txt
+++ b/render/CMakeLists.txt
@@ -2,8 +2,8 @@ add_library(wlr-render STATIC
 	matrix.c
     wlr_renderer.c
     wlr_surface.c
-    gles3/shaders.c
-    gles3/renderer.c
-    gles3/surface.c
-    gles3/util.c
+    gles2/shaders.c
+    gles2/renderer.c
+    gles2/surface.c
+    gles2/util.c
 )
diff --git a/render/gles3/renderer.c b/render/gles2/renderer.c
index 4270bd14..07647f2f 100644
--- a/render/gles3/renderer.c
+++ b/render/gles2/renderer.c
@@ -1,14 +1,14 @@
 #include <stdint.h>
 #include <stdlib.h>
 #include <assert.h>
-#include <GLES3/gl3.h>
+#include <GLES2/gl2.h>
 #include <wayland-util.h>
 #include <wayland-server-protocol.h>
 #include <wlr/render.h>
 #include <wlr/render/interface.h>
 #include <wlr/render/matrix.h>
 #include <wlr/util/log.h>
-#include "render/gles3.h"
+#include "render/gles2.h"
 
 static struct {
 	bool initialized;
@@ -16,7 +16,6 @@ static struct {
 	GLuint quad;
 	GLuint ellipse;
 } shaders;
-static GLuint vao, vbo, ebo;
 
 static bool compile_shader(GLuint type, const GLchar *src, GLuint *shader) {
 	*shader = GL_CALL(glCreateShader(type));
@@ -77,41 +76,11 @@ error:
 	wlr_log(L_ERROR, "Failed to set up default shaders!");
 }
 
-static void init_default_quad() {
-	GLfloat verticies[] = {
-		1, 1, 1, 1, // bottom right
-		1, 0, 1, 0, // top right
-		0, 0, 0, 0, // top left
-		0, 1, 0, 1, // bottom left
-	};
-	GLuint indicies[] = {
-		0, 1, 3,
-		1, 2, 3,
-	};
-
-	GL_CALL(glGenVertexArrays(1, &vao));
-	GL_CALL(glGenBuffers(1, &vbo));
-
-	GL_CALL(glBindVertexArray(vao));
-	GL_CALL(glBindBuffer(GL_ARRAY_BUFFER, vbo));
-
-	GL_CALL(glEnableVertexAttribArray(0));
-	GL_CALL(glEnableVertexAttribArray(1));
-	GL_CALL(glVertexAttribPointer(0, 2, GL_FLOAT, GL_FALSE, 4 * sizeof(GLfloat), (void *)0));
-	GL_CALL(glVertexAttribPointer(1, 2, GL_FLOAT, GL_FALSE, 4 * sizeof(GLfloat), (void *)(2 * sizeof(GLfloat))));
-	GL_CALL(glBufferData(GL_ARRAY_BUFFER, sizeof(verticies), verticies, GL_STATIC_DRAW));
-
-	GL_CALL(glGenBuffers(1, &ebo));
-	GL_CALL(glBindBuffer(GL_ELEMENT_ARRAY_BUFFER, ebo));
-	GL_CALL(glBufferData(GL_ELEMENT_ARRAY_BUFFER, sizeof(indicies), indicies, GL_STATIC_DRAW));
-}
-
 static void init_globals() {
 	init_default_shaders();
-	init_default_quad();
 }
 
-static void wlr_gles3_begin(struct wlr_renderer_state *state,
+static void wlr_gles2_begin(struct wlr_renderer_state *state,
 		struct wlr_output *output) {
 	// TODO: let users customize the clear color?
 	GL_CALL(glClearColor(0.25f, 0.25f, 0.25f, 1));
@@ -123,15 +92,41 @@ static void wlr_gles3_begin(struct wlr_renderer_state *state,
 	// for users to sling matricies themselves
 }
 
-static void wlr_gles3_end(struct wlr_renderer_state *state) {
+static void wlr_gles2_end(struct wlr_renderer_state *state) {
 	// no-op
 }
 
-static struct wlr_surface *wlr_gles3_surface_init(struct wlr_renderer_state *state) {
-	return gles3_surface_init();
+static struct wlr_surface *wlr_gles2_surface_init(struct wlr_renderer_state *state) {
+	return gles2_surface_init();
+}
+
+static void draw_quad() {
+	GLfloat verts[] = {
+		1, 0, // top right
+		0, 0, // top left
+		1, 1, // bottom right
+		0, 1, // bottom left
+	};
+	GLfloat texcoord[] = {
+		1, 0, // top right
+		0, 0, // top left
+		1, 1, // bottom right
+		0, 1, // bottom left
+	};
+
+	GL_CALL(glVertexAttribPointer(0, 2, GL_FLOAT, GL_FALSE, 0, verts));
+	GL_CALL(glVertexAttribPointer(1, 2, GL_FLOAT, GL_FALSE, 0, texcoord));
+
+	GL_CALL(glEnableVertexAttribArray(0));
+	GL_CALL(glEnableVertexAttribArray(1));
+
+	GL_CALL(glDrawArrays(GL_TRIANGLE_STRIP, 0, 4));
+
+	GL_CALL(glDisableVertexAttribArray(0));
+	GL_CALL(glDisableVertexAttribArray(1));
 }
 
-static bool wlr_gles3_render_surface(struct wlr_renderer_state *state,
+static bool wlr_gles2_render_surface(struct wlr_renderer_state *state,
 		struct wlr_surface *surface, const float (*matrix)[16]) {
 	assert(surface && surface->valid);
 	switch (surface->format) {
@@ -145,53 +140,44 @@ static bool wlr_gles3_render_surface(struct wlr_renderer_state *state,
 		wlr_log(L_ERROR, "No shader for this surface format");
 		return false;
 	}
-	gles3_flush_errors();
-	GL_CALL(glBindVertexArray(vao));
-	GL_CALL(glBindBuffer(GL_ARRAY_BUFFER, vbo));
-	GL_CALL(glBindBuffer(GL_ELEMENT_ARRAY_BUFFER, ebo));
+	gles2_flush_errors();
 	wlr_surface_bind(surface);
 	GL_CALL(glUniformMatrix4fv(0, 1, GL_TRUE, *matrix));
-	GL_CALL(glDrawElements(GL_TRIANGLES, 6, GL_UNSIGNED_INT, 0));
+	draw_quad();
 	return true;
 }
 
-static void wlr_gles3_render_quad(struct wlr_renderer_state *state,
+static void wlr_gles2_render_quad(struct wlr_renderer_state *state,
 		const float (*color)[4], const float (*matrix)[16]) {
 	GL_CALL(glUseProgram(shaders.quad));
-	GL_CALL(glBindVertexArray(vao));
-	GL_CALL(glBindBuffer(GL_ARRAY_BUFFER, vbo));
-	GL_CALL(glBindBuffer(GL_ELEMENT_ARRAY_BUFFER, ebo));
 	GL_CALL(glUniformMatrix4fv(0, 1, GL_TRUE, *matrix));
 	GL_CALL(glUniform4f(1, (*color)[0], (*color)[1], (*color)[2], (*color)[3]));
-	GL_CALL(glDrawElements(GL_TRIANGLES, 6, GL_UNSIGNED_INT, 0));
+	draw_quad();
 }
 
-static void wlr_gles3_render_ellipse(struct wlr_renderer_state *state,
+static void wlr_gles2_render_ellipse(struct wlr_renderer_state *state,
 		const float (*color)[4], const float (*matrix)[16]) {
 	GL_CALL(glUseProgram(shaders.ellipse));
-	GL_CALL(glBindVertexArray(vao));
-	GL_CALL(glBindBuffer(GL_ARRAY_BUFFER, vbo));
-	GL_CALL(glBindBuffer(GL_ELEMENT_ARRAY_BUFFER, ebo));
 	GL_CALL(glUniformMatrix4fv(0, 1, GL_TRUE, *matrix));
 	GL_CALL(glUniform4f(1, (*color)[0], (*color)[1], (*color)[2], (*color)[3]));
-	GL_CALL(glDrawElements(GL_TRIANGLES, 6, GL_UNSIGNED_INT, 0));
+	draw_quad();
 }
 
-static void wlr_gles3_destroy(struct wlr_renderer_state *state) {
+static void wlr_gles2_destroy(struct wlr_renderer_state *state) {
 	// no-op
 }
 
 static struct wlr_renderer_impl wlr_renderer_impl = {
-	.begin = wlr_gles3_begin,
-	.end = wlr_gles3_end,
-	.surface_init = wlr_gles3_surface_init,
-	.render_with_matrix = wlr_gles3_render_surface,
-	.render_quad = wlr_gles3_render_quad,
-	.render_ellipse = wlr_gles3_render_ellipse,
-	.destroy = wlr_gles3_destroy
+	.begin = wlr_gles2_begin,
+	.end = wlr_gles2_end,
+	.surface_init = wlr_gles2_surface_init,
+	.render_with_matrix = wlr_gles2_render_surface,
+	.render_quad = wlr_gles2_render_quad,
+	.render_ellipse = wlr_gles2_render_ellipse,
+	.destroy = wlr_gles2_destroy
 };
 
-struct wlr_renderer *wlr_gles3_renderer_init() {
+struct wlr_renderer *wlr_gles2_renderer_init() {
 	init_globals();
 	return wlr_renderer_init(NULL, &wlr_renderer_impl);
 }
diff --git a/render/gles3/shaders.c b/render/gles2/shaders.c
index dd7f790f..850c0618 100644
--- a/render/gles3/shaders.c
+++ b/render/gles2/shaders.c
@@ -1,5 +1,5 @@
-#include "render/gles3.h"
-#include <GLES3/gl3.h>
+#include "render/gles2.h"
+#include <GLES2/gl2.h>
 
 // Colored quads
 const GLchar quad_vertex_src[] =
diff --git a/render/gles3/surface.c b/render/gles2/surface.c
index 0ddf3ae0..278b3dc3 100644
--- a/render/gles3/surface.c
+++ b/render/gles2/surface.c
@@ -1,15 +1,15 @@
 #include <stdint.h>
 #include <stdlib.h>
 #include <assert.h>
-#include <GLES3/gl3.h>
+#include <GLES2/gl2.h>
 #include <wayland-util.h>
 #include <wayland-server-protocol.h>
 #include <wlr/render.h>
 #include <wlr/render/interface.h>
 #include <wlr/render/matrix.h>
-#include "render/gles3.h"
+#include "render/gles2.h"
 
-static bool gles3_surface_attach_pixels(struct wlr_surface_state *surface,
+static bool gles2_surface_attach_pixels(struct wlr_surface_state *surface,
 		uint32_t format, int width, int height, const unsigned char *pixels) {
 	assert(surface);
 	surface->wlr_surface->width = width;
@@ -23,7 +23,7 @@ static bool gles3_surface_attach_pixels(struct wlr_surface_state *surface,
 	return true;
 }
 
-static void gles3_surface_get_matrix(struct wlr_surface_state *surface,
+static void gles2_surface_get_matrix(struct wlr_surface_state *surface,
 		float (*matrix)[16], const float (*projection)[16], int x, int y) {
 	struct wlr_surface *_surface = surface->wlr_surface;
 	float world[16];
@@ -35,27 +35,27 @@ static void gles3_surface_get_matrix(struct wlr_surface_state *surface,
 	wlr_matrix_mul(projection, matrix, matrix);
 }
 
-static void gles3_surface_bind(struct wlr_surface_state *surface) {
+static void gles2_surface_bind(struct wlr_surface_state *surface) {
 	GL_CALL(glActiveTexture(GL_TEXTURE0 + 1));
 	GL_CALL(glBindTexture(GL_TEXTURE_2D, surface->tex_id));
 	GL_CALL(glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_LINEAR));
 	GL_CALL(glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_LINEAR));
 }
 
-static void gles3_surface_destroy(struct wlr_surface_state *surface) {
+static void gles2_surface_destroy(struct wlr_surface_state *surface) {
 	GL_CALL(glDeleteTextures(1, &surface->tex_id));
 	free(surface);
 }
 
 static struct wlr_surface_impl wlr_surface_impl = {
-	.attach_pixels = gles3_surface_attach_pixels,
+	.attach_pixels = gles2_surface_attach_pixels,
 	// .attach_shm = TODO
-	.get_matrix = gles3_surface_get_matrix,
-	.bind = gles3_surface_bind,
-	.destroy = gles3_surface_destroy,
+	.get_matrix = gles2_surface_get_matrix,
+	.bind = gles2_surface_bind,
+	.destroy = gles2_surface_destroy,
 };
 
-struct wlr_surface *gles3_surface_init() {
+struct wlr_surface *gles2_surface_init() {
 	struct wlr_surface_state *state = calloc(sizeof(struct wlr_surface_state), 1);
 	struct wlr_surface *surface = wlr_surface_init(state, &wlr_surface_impl);
 	state->wlr_surface = surface;
diff --git a/render/gles3/util.c b/render/gles2/util.c
index a3aa87f3..9498a1cd 100644
--- a/render/gles3/util.c
+++ b/render/gles2/util.c
@@ -1,10 +1,10 @@
 #include <stdlib.h>
 #include <stdbool.h>
-#include <GLES3/gl3.h>
+#include <GLES2/gl2.h>
 #include <wlr/util/log.h>
-#include "render/gles3.h"
+#include "render/gles2.h"
 
-const char *gles3_strerror(GLenum err) {
+const char *gles2_strerror(GLenum err) {
 	switch (err) {
 	case GL_INVALID_ENUM:
 		return "Invalid enum";
@@ -21,7 +21,7 @@ const char *gles3_strerror(GLenum err) {
 	}
 }
 
-bool _gles3_flush_errors(const char *file, int line) {
+bool _gles2_flush_errors(const char *file, int line) {
 	GLenum err;
 	bool failure = false;
 	while ((err = glGetError()) != GL_NO_ERROR) {
@@ -31,7 +31,7 @@ bool _gles3_flush_errors(const char *file, int line) {
 			_wlr_log(L_ERROR, "[%s:%d] Fatal GL error: out of memory", file, line);
 			exit(1);
 		} else {
-			_wlr_log(L_ERROR, "[%s:%d] GL error %d %s", file, line, err, gles3_strerror(err));
+			_wlr_log(L_ERROR, "[%s:%d] GL error %d %s", file, line, err, gles2_strerror(err));
 		}
 	}
 	return failure;